easyBTX is an indie app and currently unsigned (no paid signing certificate), so your computer warns you the first time. That's expected for small indie apps, and you only clear it once.

On Mac, macOS says it "can't verify the developer." Here's how to open it:

1. Double-click easyBTX. When macOS blocks it, click Done.
2. Open System Settings → Privacy & Security.
3. Scroll down to the easyBTX notice and click Open Anyway.
4. Confirm with Touch ID or your password. You only do this once.

If instead macOS says easyBTX is "damaged and can't be opened", that's just the download-quarantine flag on an unsigned app. Drag easyBTX into your Applications folder, then run this once in Terminal (Applications → Utilities → Terminal):

xattr -dr com.apple.quarantine /Applications/easyBTX.app

Then open easyBTX normally. It's safe. That command only clears the "downloaded from the internet" tag macOS adds to unsigned apps; it doesn't change the app.

On Windows, SmartScreen shows "Windows protected your PC." Click More info, then Run anyway, and finish the install. That's the standard prompt for an unsigned indie app, not a sign that anything's wrong. There's no xattr step on Windows.